内陆水域鱼类放养捕捞模型及应用

用矩阵形式描述了放养捕捞的数学模型，对主要变量－回捕率的估测方法（渔获物年龄组成法、历史放养捕捞数据法和标志回捕法）进行了说明。用渔获物年龄组成和历史放养捕捞数据法，估算了大伙房水库鲢、鳙的牧养回捕率，还对目前牧养群体资源研究中参数求解问题提出了相应的见解。     

常州市城市内河常见鱼类资源及保护的研究

为了更好的评价常州城市内河治理后的生态环境。于2012年8—12月连续3次对江苏省常州市新北区运北水系的三井河、柴支浜河、北塘河、通济河、澡港河进行了常见鱼类群落调查。调查共捕获鱼类331尾、3523.55 g,隶属3目3科11属12种。鲤形目中的鲫（餐）、贝氏（餐）为优势种（IRI≥1000）,似鳊、麦穗、乌鳢等为常见种（IRI≥100）,合鳃目中黄鳝等为稀有种（IRI≤100）。Margalef丰富度指数以4#易买得最高,达到1.924,而1#塘北桥,7#勤丰桥为较高,以11#通济河西为最低;Shannon-Wiener多样性指数以7#勤丰桥最高,达到1.431,而10#三井河桥,1#塘北桥为较高,以13#通济河东为最低;Pielou＇s Evenness Index均匀度指数以3#三井桥最高,达到0.978,而10#三井河桥,1#塘北桥为较高,以13#通济河东为最低;多样性指数和均匀度指数与高锰酸盐指数、BOD5、石油类、总氮、氨氮等环境因子呈显著负相关关系,多样性指数和发光细菌急性毒性及丰富度指数呈显著正相关关系。鱼类种类调查结果可为常州市运河鱼类资源保护和利用提供参考,同时也为生态环境的修复进展提供有力证明。     

1976-2009年青藏高原内陆湖泊变化的时空格局与过程

为了揭示近几十年来气候变化条件下青藏高原内陆现代湖泊的时空变化规律,在1976年、1990年、2000年和 2009年4个时段青藏高原内陆湖泊变化制图结果的基础上,重点分析流域内湖泊变化的时间过程和流域间湖泊变化的空间模式,并从气候要素变化、流域水源补给等方面探讨影响内陆湖泊变化的主要因素。结果表明：流域内湖泊总面积1970-1990年萎缩、1990-2009年扩张,1976-2009年呈现扩张的变化趋势,年均降水量和年均气温的变化趋势较好地解释了湖泊由萎缩到扩张的变化状况。从湖泊变化的空间格局来看,不同地域、不同流域的湖泊面积变化模式及其剧烈程度与流域内的水源补给方式有关,以雪冰融水补给的流域内湖泊总面积变化的剧烈程度远不及以冻融水补给为主的流域。因此,区域气候的变化是近几十年来高原内陆湖泊整体显著萎缩或扩张的主要原因,而流域水源补给的方式诠释了湖泊变化的区域差异。     

堆肥与化肥配施对甘肃河西内陆灌区玉米生长及产量的影响

研究了堆肥与化肥配施对甘肃河西内陆灌区玉米生长及产量的影响。结果表明,堆肥与化肥配施玉米农田中全年光能利用率以处理7(堆肥60 000 kg/hm2+磷二铵210 kg/hm2)最高,为0.884%;玉米水分利用率、经济产量、生物产量和经济总收入均以处理7最高,其中,经济产量水分利用效率为46.85 kg/mm,生物产量水分利用效率为85.72 kg/mm,经济产量为17 280.99 kg/hm2,生物产量为30 886.09 kg/hm2,经济总收入为35 922.5元/hm2。     

Heavy metal contamination of urban topsoil in a petrochemical industrial city in Xinjiang,China

Heavy metal pollution is a widespread phenomenon in many countries of the world.In this study,we conducted a field investigation to assess the status of heavy metal pollution in urban soils of Dushanzi,a district of Karamay city in Xinjiang,China.A total of 56 soil samples in the topsoil layer of 0–15 cm were collected within the urban area and seven elements(Cu,Zn,Cd,Pb,Cr,As and Ni) were analyzed.The mean concentrations of these metals were all higher than their corresponding background values of soils in Xinjiang.We used the pollution index and ecological risk index to assess the degree of heavy metal pollution and the potential ecological risk of urban soils.The pollution index values of Cu,Zn,Cd,Pb,Cr,As and Ni were 1.81,1.35,4.64,1.27,1.80,1.39 and 1.22,respectively;and the potential ecological risk index values for them were 12.03,1.79,185.05,8.39,4.78,18.44 and 1.79,respectively.These results indicated that urban soils in Dushanzi were polluted by heavy metals to some extent and demonstrated a high ecological risk,as influenced by industrial activities.Cd was the key element for the metal pollution of urban soils in the study area.Correlation analyses,principal component analysis coupled with the spatial distribution maps of element concentrations further revealed that heavy metal pollution of urban soils can be mainly attributed to petrochemical industry,coal chemical industry,traffic and commercial activities.     

Fishery yields vary with land cover on the Amazon River floodplain

Inland fisheries underpin food security in many tropical countries. The most productive inland fisheries in tropical and subtropical developing countries occur in large river–floodplain systems that are often impacted by land cover changes. However, few studies to date have assessed the effects of changes in floodplain land cover on fishery yields. Here, we integrated fisheries and satellite‐mapped habitat data to evaluate the effects of floodplain deforestation on fishery yields in 68 floodplain lake systems of the lower Amazon River, representing a wide range in relative amounts of woody, herbaceous and non‐vegetated land cover. We modelled relative fish yields (fish capture per unit effort [CPUE]) in the floodplain lakes as a function of the relative amounts of forest, shrub, aquatic macrophyte and bare/herbaceous habitats surrounding them. We found that forest amount was positively related (p = .0003) to multispecies CPUE. The validity of these findings was supported by rejection of plausible alternative causative mechanisms involving habitat‐related differences in amount of piscivores, fishing effort, lake area, and habitat effects on CPUE of the nine taxa dominating multispecies yields. Our results provide support to the idea that removal of floodplain forests reduces fishery yields per unit effort. Increased protection of floodplain forests is necessary to maintain the food, income and livelihood security services provided by large river–floodplain fisheries.     

Rhamphicarpa fistulosa,a widespread facultative hemi‐parasitic weed,threatening rice production in Africa

Rhamphicarpa fistulosa is a facultative hemi‐parasitic plant of the Orobanchaceae family, adapted to wet soils. Apart from tropical Australia, it is only found in sub‐Saharan Africa, where it is considered a minor weed in cereal crops such as rice. Due to this status, the species has received only sporadic attention. Recent field observations and encounters with rice farmers in several African countries showed that R. fistulosa is, however, a more serious and increasing production constraint than previously thought. Results from a systematic literature review and a global herbarium study support this. The species has a broad distribution over Africa (at least 35 countries from Madagascar to Senegal and from Sudan to South Africa) and a wide range in altitude (0–2150 m a.s.l.) and environment (waterlogged swamps to moist free‐draining uplands). Rhamphicarpa fistulosa is relatively independent and persistent because of the presumably wide host range, the facultative nature of its parasitism and its prolific seed (estimated 100 000 seeds m^?2 under moderate infestation levels). Finally, R. fistulosa causes severe yield losses (average 60%) and high regional annual economic losses (estimated US $175 million), while effective control options are scant and awareness of the species among important R&D stakeholders is almost absent. An integrated approach is advocated to assist the rice sector to reduce current R. fistulosa‐inflicted losses and to prevent further spread of the species into new areas.     

Risk screening of non‐native freshwater fishes in Croatia and Slovenia using the Fish Invasiveness Screening Kit

The Fish Invasiveness Screening Kit (FISK) version 2 was used to assess the invasiveness potential of 40 introduced and translocated freshwater fish species to Croatia and Slovenia. Based on a priori classification of invasiveness, receiver operating characteristic analysis of FISK scores from two independent assessors resulted in a statistically significant calibration threshold of 11.75. This indicated that FISK was able to discriminate reliably between non‐native species likely to pose a high risk of being invasive and those likely to pose a medium or low risk of invasiveness. Seven species were categorised as ‘medium risk’ and the other 33 as ‘high risk’, whereas no species was categorised as ‘low risk’. The two highest scoring species were European catfish Silurus glanis and North African catfish Clarias gariepinus. Mean scores for all species classified a priori as invasive were ranked as ‘high risk’ sensu lato and fell into the ‘moderately high risk’ subcategory. FISK proved to be a valid tool for assessing the risks posed by non‐native fishes in Croatia and Slovenia. For this reason, it can be adopted as a reliable tool for the prevention of new translocations or introductions of potentially invasive species in the risk assessment area, as well as to assist in decisions regarding future management (i.e. monitoring, control and eradication) and conservation strategies.     

When is a fisher (not) a fisher? Factors that influence the decision to report fishing as an occupation in rural Cambodia

In the developing world, the majority of people who fish in inland areas do so primarily for subsistence needs. This suggests that survey or census questionnaires which collect information concerning the occupations of respondents will underreport the number of people who fish, and corollary to this, misrepresent dependence on fishing as a support service for food and supplemental income. This study uses the results of a household survey conducted in 37 villages across Cambodia to quantify the amount of fishing that is done by inland fishers who do not report fishing as a primary or secondary occupation. The study also identifies the household characteristics which influence the decision of an individual who fishes to report fishing as an occupation. Fifty‐eight percent of households whose members engaged in fishing activities did not report fishing as an occupation. Individuals whose household owned farmland, earned off‐farm income and fished primarily for subsistence needs were significantly less likely to report fishing as an occupation. When assessing the importance of fishing to inland rural communities for the purposes of rural planning and policy development, relying solely on census‐style occupation or employment data will misrepresent the contributions of subsistence fishing to household welfare.     

Hatchery seed production of giant freshwater prawn,Macrobrachium rosenbergii using inland ground saline water in India

The suitability of inland saline water (ISW) from the Lahli‐Baniyani Fish Farm, Rohtak was investigated for the larval rearing of giant freshwater prawn (GFP), Macrobrachium rosenbergii. Six experiments were conducted. In Experiment‐I, 54% of the larvae metamorphosed to postlarvae (PL) in constituted seawater (CSW) whereas total mortality occurred at larval stages (LS)‐II and LS‐III in ISW with salinity of 12 g L^?1. Larvae survived to LS‐IV in Experiment‐II, when ISW was supplemented with K⁺~ SW. In Experiment‐III, total hardness in ISW was reduced serially, but K⁺ ~ SW was supplemented. The larvae did not survive beyond LS‐V. In Experiment‐IV, ISW was amended with different ratios of Mg²⁺/Ca²⁺ and K⁺ ~ SW. The larvae successfully metamorphosed to postlarvae with highest survival of 51.6% in Mg²⁺/Ca²⁺ ratio of 2.5. In Experiment‐V, eight larval cycles were run with water quality used in Experiment V, where all the cycles produced PL's with a survival rate of 20–67%. In Experiment VI, the larvae were reared in Mg²⁺/Ca²⁺ ratio of 2.5 and different levels of K⁺ to optimize its requirement. The ISW amended with K⁺ 80% ~ SW and Mg²⁺/Ca²⁺ ratio of 2.5 was found to be commercially suitable for the seed production of GFP.